As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER THE AIRCRAFT ARRIVED, THE GATE AGENT WAS NOT ABLE TO OPEN THE FOWARD ENTRY L1 DOOR. AIRCRAFT WAS GROUNDED. MAINTENANCE FOUND A SCREW BROKEN AT THE UPPER RADIUS LINK THROUGH GUIDE ARM TO LOWER RADIUS LINK ON FOWARD ENTRY DOOR ATTACH POINT. MAINTENANCE REPLACED THE PIN ASSEMBLY AND HARDWARE IAW MM 521-11-21-400 AND PERFORMED SATISFACTORY OPS CHECK.